Reusable seal for sewage basins

ABSTRACT

A sewage basin arrangement is provided having a flange surface about the opening of the basin, a continuous groove formed in that flange surface which is spaced apart from the fastener apertures and disposed between those apertures and the opening, and a length of compressible sealing tape mounted within the groove and protruding in part from the groove. The tape is secured to the groove by an adhesive disposed within the groove. The ends of the tape laterally overlap within the groove.

BACKGROUND AND SUMMARY OF THE INVENTION

[0001] The present invention relates generally to sewage basins, and, more particularly, to methods and apparatus for sealing of the lids to the openings in sewage basins.

[0002] A variety of sewage basins are known for receiving fluids that are both unsanitary and odorous. Since pumps and other equipment needing periodic inspection, cleaning and/or repair are often mounted within sewage basins, removable lids have been needed for attachment to the sewage basins to permit limited access to the interior regions of the basins through openings in the basin. When the lids are closed upon the sewage basins it has been preferable to have a liquid and air tight seal between the lid and the basin.

[0003] Such sewage basins have typically been formed with a rim having a flange surface about the circumference of the opening in the basin. The corresponding lids have typically been formed so as to engage the flange surface over the opening. A plurality of aligned apertures in the lids and flange surface have been used to receive fasteners for retaining and securing the lid to the basin. These fasteners were typically threaded bolts passing through the flange surface and the lid and retained thereto by mating nuts.

[0004] Previously, the liquid and air tight seals between the lid and the basin have been achieved by mounting a length of compressible tape to the flange surface at the location of the apertures in the flange surface. This tape was relatively flat and had an adhesive on one side to secure the tape to the flange surface prior to mounting the lid to the basin. Usually, the tape overlaid the apertures so that the bolts would also be subject to a fluid seal as the bolts passed through the tape. The tape was laid in place on the flange surface with the ends of the tape overlapping vertically. The installation of the tape was often done at the installation site of the basin, rather than at the basin manufacturing facility. The tape was typically formed from a closed cell polyethylene material of approximately ⅛ inch thickness.

[0005] Unfortunately, these prior seals suffered some disadvantages in certain situations. Over time, as the lid compressed the tape to the flange surface, the tape became subject to “compression set,” meaning that a permanent deformation of the tape was created that reduced its effective compressibility in subsequent applications. Thus, if the lid needed to be opened and then re-closed, the tape would need to be replaced at the usage site in order to obtain a effective air and liquid seal again. That procedure often involved a time-consuming task of scraping off the old tape and its adhesive prior to applying a new tape. Given the contents of the basin subsequent to initial installation and the environment of the basin location, taking additional time for a complete new tape installation was often an unpleasant experience for the service personnel. As a result, short cuts were sometimes used, such as merely applying a bead of caulking about the old tape and then setting the lid back in place on the rim. However, such caulking was not always as effective as would be desired in establishing a new seal and would act as an excessive adhesive restricting lid removal the next time that the lid had to be removed.

[0006] In addition, while in theory forming a seal about the fastener bolts coincident with the lid seal was a good idea to simultaneously prevent excess corrosion of the bolts and leakage into or out of the basin, the process of puncturing the sealing tape to fit the bolts through it was time consuming, tedious at the basin installation site and occasionally resulted in tears of the tape and leaks past the tape. Further, given the flat nature of the tape and its extra width to encompass the bolt diameter as well, if full attention was not given to initial placement of the tape bends or folds in the tape would be formed as it was placed onto the flange surface. These bends or folds created vertical non-uniformities or gaps in the seal which could allow leakage of air and/or liquids into or out of the basin. Similarly, the vertical overlap of the ends of the tape created a vertical non-uniformity and gaps that could allow such leakage. Use of flat O-rings without end overlaps had been considered, but was often found to be inadvisable due to its additional costs and the difficulty in precise placement and proper setting.

[0007] A further difficulty that occasionally arose with excessive compression of the tape or with use of a flatter tape to facilitate scraping off after each use was the “bleeding” of the tape adhesive from the interface between the flange surface and the tape upwards to the lid. As a result, the adhesive acted to retain the lid to the flange surface as well, thus making removal of the lid more difficult.

[0008] Accordingly, it is an object of the present invention to provide an improved method and apparatus for sealing of sewage basins. In particular, it is an object of the present invention to provide a sewage basin seal that:

[0009] a. Is reusable for a sustained period of time and numerous openings and closings of the basin lid,

[0010] b. Is more reliable against leakage initially and for longer periods of time,

[0011] c. Is more able to resist compression set and/or adhesive bleed,

[0012] d. Is less costly and time consuming to install and maintain,

[0013] e. Permits greater flexibility in application to different pressure applications,

[0014] f. Can be installed at the basin manufacturing facility, and

[0015] g. Permits more efficient removal and re-application of the lid to the basin.

[0016] These and other objects of the present invention are obtained by the provision of a sewage basin arrangement having a flange surface about the opening of the basin, a continuous groove formed in that flange surface which is spaced apart from the fastener apertures and disposed between those apertures and the opening, and a length of compressible sealing tape mounted within the groove and protruding in part from the groove. The tape is secured to the groove by an adhesive disposed within the groove. The ends of the tape laterally overlap within the groove.

[0017] Other objects, advantages and novel features of the present invention will become readily apparent to those skilled in the art upon consideration of the following drawings and detailed description of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 shows a side view of a sewage basin arrangement incorporating the present invention.

[0019]FIG. 2 shows a top view of the sewage basin of FIG. 1 with the lid mounted for covering the basin opening.

[0020]FIG. 3 shows an enlarged cross-sectional view along line A-A of the rim portion of the sewage basin of FIG. 1 with the sealing tape removed.

[0021]FIG. 4 shows a further enlarged partial cross-sectional view along line B-B of the rim portion of the sewage basin of FIG. 1 with the sealing tape and fastener elements removed.

[0022]FIG. 5 shows an enlarged top view of the sewage basin of FIG. 1.

[0023] The degree of enlargement is not the same in FIGS. 3-5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0024] The figures, which illustrate a preferred embodiment of the present invention for a particular application, show a sewage basin arrangement which includes a basin 10 and a lid 30. The basin is, for example, a solid body formed from a plastic, injection molded material, such as structural foam, and includes an interior region or area 12 for receiving sewage and within which supplemental equipment, such as pumps and conduits, may be mounted or positioned as desired for a particular application. The basin is formed with an opening 14, preferably at the upper end thereof, for permitting access to the interior region. A rim 16 is formed on the basin about opening 14, preferably extending completely about the circumference of the opening. The rim includes a flange surface 18 adjacent to opening 14. This flange surface includes, for example, a flat recessed portion 20 for receiving lid 30. The lid is preferably formed with a flat lower or underside portion 32 about its circumference for mating engagement with recessed portion 20.

[0025] While recessed portion 20 and lower portion 32 are illustrated herein as being flat, other configurations are envisioned by the present invention, so long as those members can be at least somewhat matingly joined to permit a fluid seal between them. Similarly, although opening 14 and lid 30 are illustrated as being circular in configuration, other shapes are envisioned by the present invention, so long as lid 30 is configured to cover the opening with at least some overlap onto flange surface 18.

[0026] In order to apply force to lid 30 to retain it to rim 16, a plurality of fasteners 40 are employed. The particular nature of the fasteners is not the subject of this invention. In preferred embodiments, nuts and bolts can be employed for this purpose. Conventional arrangements for such fasteners can be employed with the present invention. For example, such nut/bolt combinations would, for example, be equally spaced about the periphery of the rim. Flange surface 18 includes, for example, apertures 22 therein for receiving each of the bolts. Lid 30 includes a corresponding apertures which are aligned with apertures 22 for also receiving the bolts. The mating nuts for each bolt can be applied over lid 30 or under rim 16, as may be convenient to a particular application.

[0027] The present invention includes a sealing assembly mounted between the rim and the lid for providing a fluid tight seal against the passage of air and/or liquid into or out of the basin through opening 14 past flange surface 18. This assembly includes a groove 24 formed on recessed portion 20. This groove is preferably of uniform depth and extends continuously around rim 16 to completely encircle opening 14. Groove 24 is positioned so as to be spaced between apertures 22 and opening 14. Groove 24 is also preferably spaced apart from apertures 22 so that the bolts or other fasteners used in the apertures do not enter groove 24 and come into contact with or interfere with any sealing material placed within groove 24. Groove 24 is further positioned on recessed portion 20 so as to be aligned with and adjacent lower portion 32 of lid 30 when the lid is mounted onto recessed portion 20.

[0028] The sealing assembly also includes a strip or length of tape 26 formed from compressible material and mounted within groove 24. Preferably, tape 26 protrudes out of groove 24 in part so as to extend toward and be engagable with lower portion 32 of lid 30 when the lid is mounted onto recessed portion 20. Groove 24 may, in some preferred embodiments, be formed with an enlarged overlap pocket 28. The ends of tape 26 are positioned so as to laterally overlap within pocket 28 rather than overlap vertically on top of one another. This lateral overlap prevents the formation of a greater localized vertical dimension or elevation of the tape toward the lid at the point of the overlap. In applications where opening 14 is of circular configuration, the overlap of the ends of tape 26 will preferably be disposed radially of the central axis 15 of that opening. In embodiments of the present invention where groove 24 does not include pocket 28, the ends of tape 26 can be compressed within the groove to also maintain a lateral overlap without an enlarged vertical dimension. As shown in the figures, the vertical direction referred to herein is along the direction of axis 15 while the lateral or radial direction referred to herein is generally orthogonal or at an angle to axis 15.

[0029] In an exemplary application where opening 14 is 18 inches in diameter, groove 24 has been formed with a flat bottom and depth of ⅛ inch and a neoprene tape of ⅜ inch thickness has been mounted in that groove with ¼ inch projection toward the lid. Upon fastening of the lid to the rim, the tape has thereby been compressed to no more than one third of its original dimension.

[0030] To assist in retaining tape 26 within groove 24, an adhesive can be employed, either as a separate film or application to groove 24, or, more preferably, as applied to one side of tape 26. Usually, it will be preferable to have the adhesive applied to the side of tape 26 which is to engage the bottom of groove 24. Groove 24 is shown to have a flat bottom of uniform depth in the figures, and that configuration can aid in isolation of the tape adhesive from the lid. In other embodiments, however, groove 24 can have different and even irregular configurations, perhaps even to assist in retaining tape 26 without an adhesive. However, in many embodiments it will be advantageous from a sealing perspective to have the configuration of groove 24 match the configuration of the side of tape 26 which is to be inserted within the groove so as to present an even sealing surface to lower portion 32 of the lid. Even where groove 24 retains the flat and uniform configuration, in particular embodiments differently sized and shaped tapes can be used to accommodate the pressures needed to seal against in particular applications.

[0031] When installing tape 26, it has been found to be advantageous to first position one end of the tape within pocket 28 and then wrap the tape around groove 24 to return to pocket 28. Excess tape length can be trimmed off by the installer so that the tape does not protrude past pocket 28.

[0032] While the present invention has been described above with regard to certain preferred embodiments, it will be clear from this description that the invention contemplates a variety of modifications without departing from its novel and unobvious features. Accordingly, the spirit and scope of the present invention are only limited by the terms of the claims defined below. 

What is claimed is:
 1. Sewage basin arrangements comprising: a basin having an opening to the interior of the basin, a lid to cover the opening, a rim formed on the basin about the opening, a plurality of fasteners mounted to the rim and engagable with the lid, a sealing assembly mounted between the rim and the lid, the sealing assembly being disposed inwardly of the fasteners toward the opening, the sealing assembly including a length of compressible material, mounted within a groove formed in the rim, with a portion thereof protruding out of the groove and toward the lid, and the depth of the groove and the compression material being selected so as to avoid compression set then the lid is secured against the compression material to cover the opening.
 2. The arrangements according to claim 1 wherein the length of compressible material is formed as a tape and an adhesive is provided to maintain tape contact with the groove, that adhesive being disposed so as to avoid contact with the lid when the lid is secured against the compressible material to cover the opening.
 3. The arrangements according to claim 2 wherein the ends of the tape avoid creating a localized elevation of the tape toward the lid.
 4. Sewage basin arrangements comprising: a basin having a solid body surrounding an interior region and having an opening in the solid body which provides access to the interior region, a lid dimensioned so as to at least cover the opening, a rim formed on the basin about the circumference of the opening and providing a flange surface about that circumference, a plurality of apertures spaced about the flange surface for receiving fasteners to secure the lid to the rim, a sealing assembly mounted between the flange surface and the lid to provide a fluid tight seal between the flange surface and the lid, the sealing assembly including: a groove mounted in the flange surface, the groove being formed between the apertures and the opening and spaced apart from the apertures, and a length of compressible tape having a first end and a second end and mounted so as to rest within the groove and protrude at least in part from the groove and toward the lid.
 5. The arrangements according to claim 4 wherein the tape has an adhesive on one side to retain the tape within the groove.
 6. The arrangements according to claim 5 wherein the adhesive is placed upon the tape and the tape is mounted within the groove and the groove is dimensioned so as to prevent contact between the adhesive and the lid when the lid is secured to the basin.
 7. The arrangements according to claim 4 wherein the ends of the tape laterally overlap within the groove. 